Health, Nutrition and Hygiene
This domain covers nutrients, a balanced diet, deficiency diseases, personal and community hygiene, communicable disease prevention, first aid and adolescent health. Questions often ask you to match a deficiency with its symptom or choose a safe public-health action.
Core rules and concepts
- A balanced diet supplies carbohydrates, proteins, fats, vitamins, minerals, fibre and water in the right proportions.
- Protein is needed for growth and repair; carbohydrates and fats are energy sources.
- Vitamin A deficiency causes night blindness; vitamin C deficiency causes scurvy; iron deficiency causes anaemia; iodine deficiency can cause goitre.
- Communicable diseases spread by air, water, food, vectors or contact; hygiene interrupts these routes.
- Vaccination exposes the body to an antigen and builds immunity before natural infection.
- ORS replaces water and salts lost in diarrhoea; handwashing with soap reduces transmission.
- Antibiotics act on bacteria, not viruses.
Worked example
A child with diarrhoea is given ORS. The standard home preparation is 1 litre of clean, boiled and cooled water, 6 level teaspoons of sugar and half a teaspoon of salt. The sugar helps sodium and water absorption, while the salt replaces lost sodium. If the mixture is too concentrated, water may be drawn into the gut and diarrhoea can worsen; if too dilute, electrolytes are not replaced. The child should also be given zinc and food as advised, and urgent care is needed if dehydration is severe.
Traps that cost marks
- Thinking all fats are harmful; some fats are essential in small amounts.
- Using antibiotics for a viral cold.
- Believing vaccination treats an illness already established rather than preventing it.
- Making ORS by guesswork rather than the correct proportion.
- Confusing personal hygiene with community hygiene.